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Ceramic Metal Halide (CMH)

GreenThumb14

GreenThumb14

Member
Azeotrope said:
GreenThumb - I am in a fully enclosed set-up using CO2 and rives is correct. It will not double your yield. When applied correctly with reasonable temp, humidity and nutrient parameters, it will allow for maximum growth rate and if you had all of those dialed and then added CO2, a yield increase should be seen. However, as I found out recently, everything else has to be dialed.

For example, I was on track for a great cycle, but had an unfortunate moment that put my girls in 121F for about 30-45min. Lost some tops and deffinetly slowed them down. Recovered now and on track, but all the CO2 in the world won't fix that moment.

Please also note, that there is a lot of "old mythology" regarding CO2 and running higher temps and really high PPM of CO2 as the way to go. I would suggest looking for Spurr's good write ups on why a dialed in +80f lights on and +70F lights off and right around 1000ppm is very reasonable.

At any rate, don't get too excited and go nuts with the set-up....... Make sure you test and dial in everything and that may take some time.

Best of luck to you! Azeo
Click to expand...

I've been working on my cab for over a year now, so I have all the electronics and environmental control systems down.

I had a mistake like your temperature one happen a while back. Almost started a fire. Since then added in components and a few lines of code to stop that from happening again.

Thanks for the CO2 info, I'll search for Spurr's write ups.

How did you like using the retro white bulb? I really wanted to and completely set out to use the 315w elite 942 bulb but couldn't find a digital ballast for it and just couldn't see myself paying the $500 for the GEL kit. I even spent days hunting down end-user suppliers of the PGZ sockets and bought one... bah!
 
Azeotrope

Azeotrope

Well-known member
Veteran
I picked up a couple retro-whites at an electrical supply house like 2days after their release and never used anything else other than for supplimental. I saw a brochure on the counter next to a couple on display and the spectral graph looked awesome! So I grabbed two ($33.00each!). They produced every bit as well in terms of yield for me and plant health, node spacing and temps were all improved. I had been working a couple of cuts that I had from some NL5xHaze and a local Seattle area beauty and knew them very well so it was a fair test going from Eye Hortilux and Son Agro bulbs.

There are a few good options for the CDM s as far as ballasts go. I called CeraTek and they offered to sell me a kit for a reasonable price. I know that you can fleabay a philips ballast here and there. I got 2 for like $45.00.

If you order any more sockets, be careful. Look back a bit at my post on fairly recent design changes and new bulbs. I know that lightingsupply.com has them for sale, but I would call and ask before ordering.
 
GreenThumb14

GreenThumb14

Member
Would you recommend that I supplement my 250w cdm with a 150 or 250w son agro? I'm really trying to pull a nice yield out of a relatively short time and I know that a lot of other things go in to this but I do not want to be light deficient. I can do a store brand digital HPS and bulb for less than $100 and it would fit nicely in the hood with the cdm.

I saw your post about the unannounced change in base style but I won't be messing with anything but mogul for a little while. Good to know though and keep in mind for down the road. I really liked the small diameter of the Elite bulbs.

Can you tell me anything about Ceratek? I tried Googling them but only came across products from EYE and the ballast page on their website comes up 404.

Any advice on my scrog setup, it's 3x2, 6sq/ft... I was thinking either 1 big plant or 2 or 3 smaller ones. I'd like to keep my veg time short going quickly as possible from seed to harvest (Clones later...) but not sacrificing a lot of yield. I figured if I did 2 or 3 smaller plants that way I could get away with a much shorter veg time.

Thanks!
 
Azeotrope

Azeotrope

Well-known member
Veteran
HaHa! Wow, I did two edits on that last post for typo's and missed the one where I put Ceratek. CeramaTek is the GEL ballast and what I should have typed.
 
M

MrSterling

Greenthumb, I've found heat to be the limiting factor in distance from the canopy. You can get the light pretty darn close if you can keep the temps down. I'd say around a foot away was as close as I pressed it. I've definitely had moments looking and thinking it *had* to be too close, but nope. <3 CMH.
 
Azeotrope

Azeotrope

Well-known member
Veteran
Mr. Sterling is correct, heat is the limiting factor. That and light. Since I am working in a highly modified freezer, I can control temp very well and can keep the bulbs so close (like 6") that I get some bleaching! I don't think it would hurt to suppliment with an HPS, but personally, I think HPS is not worth the heat and is really a product of some oudated thinking. Plants are meant to use and do use the WHOLE spectrum and I think growers push the red light thing too far at times. Even Gavita is really pushing the addition of full spectrum to suppliment their HPS line-up. Heck, we now know that green light can be used even more efficiently than blue in high irradiance situations.

If it were me and I wanted or thought I should add more light, I'd add another CMH.
 
GreenThumb14

GreenThumb14

Member
Problem with adding another CMH is what ballast to use... Has to be quiet, can't have it humming away and I can't have something that throws a ton of heat and obviously don't want to pay like I did for the Accendo ($210). That is why I thought of a cheap HPS setup. Not that I WILL need more light, but just in case I do I would like to have something planned out.
My cabinet is also mechanically temperature controlled, like your freezer, so I can maintain whatever temps and humidity I desire.

Any enlightenment on this?
 
GreenThumb14

GreenThumb14

Member
Uh! There is a 150w version! Nice, only $18 on Amazon.com!

So this should give good results then?
http://www.ballastshop.com/120-mh150-hid-electronic-ballast.html

with
http://www.usa.lighting.philips.com/pwc_li/us_en/connect/tools_literature/downloads/p-5432.pdf

150W version.

Should I go with 3K or 4K? It'll be used the entire grow. Looking at spd for retro white, it looks like I would be better to enhance blue end with 4K bulb. But I have no idea what the spd looks like for that cmh 4k bulb, either...
 
Azeotrope

Azeotrope

Well-known member
Veteran
I have used both the 4k and 3k. I am a fan of the 4k myself. The ballast you linked to is a square wave output and should be fine with that bulb. Good way to go.
 
Anti

Anti

Sorcerer's Apprentice
Veteran


With my bare bulb vert coliseum setup (two tiers of plants in a rectangular shape around two vertically oriented 400w CMH) one small 12" fan each on their lowest setting and sitting a couple of feet beneath each bulb + 2x/minute extraction kept my room temps in line. I too was able to get my plants close enough for bleaching. (Anything closer than 3-4 inches away)


I was able to get pretty close to the bulbs:


If the hum from the mag ballasts is an issue, build a muffler box to keep the ballasts in.

If my next run is indoor, I am contemplating stacking 3x400w CMH and doing a side by side with 2x600 HPS stacked, with racks of plants encircling them to see which is a more efficient use of wattage.

Something like this:

 
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R

Ranger

Member
that's one of the things i love about these bulbs, open air rated. i know i have never, but wonder if anyone ever researched the loss of lumens, PAR wattage or color rendition through the glass hoods of the HPS units. i would imagine us CMH users are gaining quite a bit of both over bulbs that require glass covers and hoods.

nice grow btw Anti, making me consider doing a vertical run one of these days.
 
U

unthing

10% loss of light and uv filtered out through glass or something like that i think? then again many of these new cdms are not open rated, compared to retrowhites.

for us euros this tech is kinda hard to obtain..no cmh resellers in europe and some new custom declaring bullshit coming up if ordering outside the eu-zone for more than 20€(at least in this country),

edit:i'll take some back..seems that cdms are foundable but no retrowhites anywhere.
 
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R

Ranger

Member
unthing said:
10% loss of light and uv filtered out through glass or something like that i think? then again many of these new cdms are not open rated, compared to retrowhites.

for us euros this tech is kinda hard to obtain..no cmh resellers in europe and some new custom declaring bullshit coming up if ordering outside the eu-zone for more than 20€(at least in this country),

edit:i'll take some back..seems that cdms are foundable but no retrowhites anywhere.
Click to expand...

that's a shame on availability for those in Europe. this really is a great bulb, especially for the money put into the system with current prices. i'll take a 10% increase any day, as i'm sure anyone would.

i use the Phillips 400 watt retros and they work very well for me.
 
GreenThumb14

GreenThumb14

Member
Azeotrope said:
I have used both the 4k and 3k. I am a fan of the 4k myself. The ballast you linked to is a square wave output and should be fine with that bulb. Good way to go.
Click to expand...

Sweet! So I can have a 400w setup for only another $120, not bad, cheaper than the GEL 315w kit and more light! Plus that bulb uses a standard medium socket which I can get at any hardware store for a few dollars.

I can wire that 150W bulb up so I can turn it on/off independently and use it to simulate sunrise/set.

I went with an air cooled hood because I read somewhere that cool tubes are actually worse on PAR because of the curvature of the glass. Whether or not it's true I don't know, but it seems logical.
 
U

unthing

quite many people run hps bare bulb and a bit more efficient than retrowhite but not as good light qualitywise or so they say.

if anybody knows good deals in europe for those medium wattage cdms let me know, the one place i found has bulbs and ballasts for it, but expensive as hell, 600 euros/800 dollars for a bulb(170€) and ballast (almost 400€) for 315 elite 3k/4k. no agros to be found, i can imagine the price on those..
 
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